Removal of protein aggregates from biologic drug products is critical due to their potential to increase antigenic response and the associated negative impact on the patients. Aggregates
may be formed during upstream or downstream operations when suboptimal purification parameters are selected.

Once formed, aggregate removal and/or reduction becomes challenging for the downstream purification process development team. Chromatography is the most traditional purification
technology used for aggregate removal; however, chromatography methods could actually increase aggregate formation as the product is exposed to harsh conditions such as low pH or
high salt. Column chromatography is also time consuming, requiring several buffers, method development, and costly technology such as purification skids and columns.

SystImmune and Sartorius are exploring an alternate technique exploiting the Virosart® Max filter. The Virosart® Max is an optimized triple-layer polyamide pre-filter specifically designed
to remove aggregates and protect the expensive downstream virus removal filter. The Virosart® Max will be operated in a simple flow through mode to demonstrate aggregate reduction in
a bi-specific antibody model.

MilliporeSigma's CHOZN® Expression System Selected for Bi-specific Antibody Development by SystImmune

Billerica, Massachusetts

Date May 16, 2017

MilliporeSigma today announced that its CHOZN® expression system will be used by SystImmune, a Seattle-based biotechnology company, for commercial development of a bi-specific antibody therapeutic.

The CHOZN® expression system is designed to deliver manufacturing-ready robust and stable producing clones with a workflow that minimizes the resources needed to complete a cell line development project. As a result, users are able to quickly evaluate more molecules in their pipeline.

"With only two scientists in our cell science department, we were able to generate more than 10 stable cell lines using this platform in a single year," said Camilla Wang, Scientist, SystImmune. "The CHOZN® platform outperformed other systems in many ways. It is easy to use, requires less time to generate final single cell clones, and most of all, the expression level is consistently higher compared to the other approaches."

Along with the CHOZN® cells, MilliporeSigma provides an expression vector, extensive user protocols, a comprehensive cell line history document and paired cGMP media and feeds. Services are offered for cell line development in the CHOZN® expression system. MilliporeSigma also offers gene engineering services using its CompoZr™ zinc finger nuclease technology to engineer CHO cell lines with characteristics attractive to biopharmaceutical developers and manufacturers, including resistance to Centinel™ technology.